DLM_CONTROLD(8) 						      cluster							   DLM_CONTROLD(8)

NAME

       dlm_controld - daemon that configures dlm according to cluster events

SYNOPSIS

       dlm_controld [OPTIONS]

DESCRIPTION

       The dlm lives in the kernel, and the cluster infrastructure (corosync membership and group management) lives in user space.  The dlm in the
       kernel needs to adjust/recover for certain cluster events.  It's the job of dlm_controld to receive these events and reconfigure the kernel
       dlm as needed.  dlm_controld controls and configures the dlm through sysfs and configfs files that are considered dlm-internal interfaces.

       The cman init script usually starts the dlm_controld daemon.

OPTIONS

       Command line options override a corresponding setting in cluster.conf.

       -D     Enable debugging to stderr and don't fork.
	      See also dlm_tool dump in dlm_tool(8).

       -L     Enable debugging to log file.
	      See also logging in cluster.conf(5).

       -K     Enable kernel dlm debugging messages.
	      See also log_debug below.

       -r num dlm kernel lowcomms protocol, 0 tcp, 1 sctp, 2 detect.  2 selects tcp if corosync rrp_mode is "none", otherwise sctp.
	      Default 2.

       -g num groupd compatibility mode, 0 off, 1 on.
	      Default 0.

       -f num Enable (1) or disable (0) fencing recovery dependency.
	      Default 1.

       -q num Enable (1) or disable (0) quorum recovery dependency.
	      Default 0.

       -d num Enable (1) or disable (0) deadlock detection code.
	      Default 0.

       -p num Enable (1) or disable (0) plock code for cluster fs.
	      Default 1.

       -l num Limit the rate of plock operations, 0 for no limit.
	      Default 0.

       -o num Enable (1) or disable (0) plock ownership.
	      Default 1.

       -t ms  Plock ownership drop resources time (milliseconds).
	      Default 10000.

       -c num Plock ownership drop resources count.
	      Default 10.

       -a ms  Plock ownership drop resources age (milliseconds).
	      Default 10000.

       -P     Enable plock debugging messages (can produce excessive output).

       -h     Print a help message describing available options, then exit.

       -V     Print program version information, then exit.

FILES

       cluster.conf(5) is usually located at /etc/cluster/cluster.conf.  It is not read directly.  Other cluster components load the contents into
       memory, and the values are accessed through the libccs library.

       Configuration options for dlm (kernel) and dlm_controld are added to the <dlm /> section of cluster.conf, within the  top  level  <cluster>
       section.

   Kernel options
       protocol
	      The  network  protocol  can  be  set  to	tcp, sctp or detect which selects tcp or sctp based on the corosync rrp_mode configuration
	      (redundant ring protocol).  The rrp_mode "none" results in tcp.  Default detect.

	      <dlm protocol="detect"/>

       timewarn
	      After waiting timewarn centiseconds, the dlm will emit a warning via netlink.  This only applies	to  lockspaces	created  with  the
	      DLM_LSFL_TIMEWARN flag, and is used for deadlock detection.  Default 500 (5 seconds).

	      <dlm timewarn="500"/>

       log_debug
	      DLM kernel debug messages can be enabled by setting log_debug to 1.  Default 0.

	      <dlm log_debug="0"/>

       clusternode/weight
	      The  lock  directory weight can be specified one the clusternode lines.  Weights would usually be used in the lock server configura-
	      tions shown below instead.

	      <clusternode name="node01" nodeid="1" weight="1"/>

   Daemon options
       enable_fencing
	      See command line description.

	      <dlm enable_fencing="1"/>

       enable_quorum
	      See command line description.

	      <dlm enable_quorum="0"/>

       enable_deadlk
	      See command line description.

	      <dlm enable_deadlk="0"/>

       enable_plock
	      See command line description.

	      <dlm enable_plock="1"/>

       plock_rate_limit
	      See command line description.

	      <dlm plock_rate_limit="0"/>

       plock_ownership
	      See command line description.

	      <dlm plock_ownership="1"/>

       drop_resources_time
	      See command line description.

	      <dlm drop_resources_time="10000"/>

       drop_resources_count
	      See command line description.

	      <dlm drop_resources_count="10"/>

       drop_resources_age
	      See command line description.

	      <dlm drop_resources_age="10000"/>

       plock_debug
	      Enable (1) or disable (0) plock debugging messages (can produce excessive output). Default 0.

	      <dlm plock_debug="0"/>

   Disabling resource directory
       Lockspaces usually use a resource directory to keep track of which node is the master of each resource.	The dlm can  operate  without  the
       resource  directory,  though,  by statically assigning the master of a resource using a hash of the resource name.  To enable, set the per-
       lockspace nodir option to 1.

       <dlm>
	 <lockspace name="foo" nodir="1">
       </dlm>

   Lock-server configuration
       The nodir setting can be combined with node weights to create a configuration where select node(s) are the master of  all  resources/locks.
       These master nodes can be viewed as "lock servers" for the other nodes.

       <dlm>
	 <lockspace name="foo" nodir="1">
	   <master name="node01"/>
	 </lockspace>
       </dlm>

       or,

       <dlm>
	 <lockspace name="foo" nodir="1">
	   <master name="node01"/>
	   <master name="node02"/>
	 </lockspace>
       </dlm>

       Lock  management will be partitioned among the available masters.  There can be any number of masters defined.  The designated master nodes
       will master all resources/locks (according to the resource name hash).  When no masters are members of the lockspace, then the nodes revert
       to the common fully-distributed configuration.  Recovery is faster, with little disruption, when a non-master node joins/leaves.

       There  is  no  special  mode in the dlm for this lock server configuration, it's just a natural consequence of combining the "nodir" option
       with node weights.  When a lockspace has master nodes defined, the master has a default weight of 1 and all non-master nodes have weight of
       0.  An explicit non-zero weight can also be assigned to master nodes, e.g.

       <dlm>
	 <lockspace name="foo" nodir="1">
	   <master name="node01" weight="2"/>
	   <master name="node02" weight="1"/>
	 </lockspace>
       </dlm>

       In which case node01 will master 2/3 of the total resources and node2 will master the other 1/3.

SEE ALSO

       dlm_tool(8), fenced(8), cman(5), cluster.conf(5)

cluster 							    2009-01-18							   DLM_CONTROLD(8)